Creamy Pasta with Mussels and Clams

Method

1. Clean the mussels by removing the byssus and scraping the shells.
2. Place the mussels in a pan, cover, and cook over high heat for about 5 minutes, shaking occasionally, until they open.
3. Remove the mussels and set aside to cool. Filter the cooking liquid through a fine sieve.
4. Clean the clams (previously purged in salted water for an hour) and cook them in the same pan, covered, for about 2 minutes until they open.
5. Remove the clams and filter the liquid.
6. In the cleaned pan, heat a drizzle of oil with parsley stems and garlic to flavor the oil.
7. Add tomato passata and tomato concentrate, rinsing the container with a little water. Cook gently for about 15 minutes.
8. Shell most of the mussels and clams, reserving a few with shells for garnish.
9. Make a parsley oil: blend parsley leaves with oil until smooth.
10. Cook linguine in boiling unsalted water until half done.
11. Remove the parsley stems and garlic from the sauce, then transfer the pasta to the pan.
12. Finish cooking the pasta in the pan, adding the reserved mussel and clam liquid as needed.
13. Remove from heat, stir in the parsley oil, then add the shelled mussels and clams.
14. Garnish with the reserved whole shellfish and serve.